Preheat oven to 400° F. Bring water to a boil in a large, deep pot. Add salt and orzo. Boil for 9 minutes. Drain in wire sieve and rinse with cold water. Drain again. Set aside. Removed sausage from casings, if necessary, and break into small pieces. Sauté over medium high heat until browned and barely cooked through. Add chopped red peppers. Remove from heat and stir in orzo and cheeses until cheese melts. Cool. Coat 13x9-inch baking pan with cooking spray. Stuff sausage-orzo mixture into whole peppers and place peppers upright in the pan. Mix breadcrumbs and pesto and spread evenly over top of the stuffed peppers. Cover with foil and bake for 45 minutes. Remove foil and bake an additional 15 minutes or until the surface is lightly browned. Serve immediately.